When a wireless subscriber first obtains wireless telecommunications service from a wireless service provider the wireless service provider dictates the mobile directory number (i.e., the "telephone number") that the subscriber's wireless terminal can be called by. Thereafter, if the wireless subscriber desires to change his or her wireless service provider, the subscriber must surrender the mobile directory number and be issued a new mobile directory number by the new wireless service provider. As anyone who has ever had to change his or her telephone number knows, it can be extremely inconvenient, especially if the number is used for business. Therefore, it would be convenient if a wireless subscriber could take or "port" his or her mobile directory number from the original wireless service provider to another. In other words, it would be convenient if a wireless subscriber could change wireless service providers without having to change the directory number of the subscriber's wireless terminal.
Consistent with ANSI Standard 41, the porting of a wireless subscriber's mobile directory number from one wireless service provider to another requires at least five distinct events to occur that are not required when the wireless subscriber changes wireless service providers without porting the mobile directory number:
(1) the Recipient wireless service provider must inform the donor wireless service provider and the Number Portability Administrative Center ("NPAC") of the intent to port the subscriber's directory number; PA1 (2) the Number Portability Database ("NPDB") must be updated with the Location Routing Number ("LRN") associated with the subscriber's directory number; PA1 (3) a record must be created in the recipient wireless service provider's Home Location Register ("HLR") for the subscriber, which record can include, for example, the new Mobile Station Identification Number ("MSIN") and/or the Mobile Directory Number ("MDN"); PA1 (4) the subscriber's wireless terminal must be re-programmed with a new Mobile Station Identification Number ("MSIN"); and PA1 (5) the subscriber's record in the donor wireless service provider's HLR must be deleted.
If all five events do not occur simultaneously, the subscriber's service can be interrupted. For example, if the Number Portability Database is updated before the subscriber's record is created in the recipient wireless service provider's HLR, or before the subscriber's wireless terminal is re-programmed with the new MSID from the recipient wireless service provider, then a call to the subscriber's wireless terminal cannot be delivered.
In contrast, if the subscriber's record is created in the recipient wireless service provider's HLR before the Number Portability Database is updated and before the subscriber's wireless terminal is re-programmed with the new MSID, then a call originating from within the recipient system will be undeliverable because the wireless terminal will not respond to the page on the Overhead Paging Channel.
Furthermore, the coordination of these five events is complicated by the fact that the disparate elements are owned and operated by different entities. For example, the donor system owns and operates its Number Portability Database and HLR, the recipient system owns and operates its Number Portability Database and HLR, and the subscriber owns and operates its wireless terminal. Therefore, a need exists for a technique that enables a subscriber's directory number to be ported from a donor wireless service provider to a recipient wireless service provider without an interruption in the subscriber's wireless service.